To provide an ignition coil for an engine capable of reducing wear of connection part due to engine vibration.
Since a spring 42 has a smaller winding diameter at both ends 42a and 42b than a winding diameter at a center part 42c, a spring load of the spring 42 is increased to reduce contact resistances at a connection part of one end 42a of the spring 42 with a high-tension terminal 41 and a connection part of another end 42b of the spring 42 with a coil side terminal 111 of an ignition plug 110. Consequently, wear of the connection parts of the spring 42 with the high-tension terminal 41 and the ignition plug 110 from engine vibration can be reduced to prevent disturbing conduction of very small electric current such as ion current and to make detection of very small electric current easy. Misjudgment with an ignition monitor utilizing change of very small electric current in a secondary side can be prevented. Desired high voltage thereby can be applied to the ignition plug 110.
FUJIYAMA TOKUICHI
TAUCHI KOJI
WADA JUNICHI
KAWAI KAZUHIDE
SANO MASAFUYU
SHIMOIDE SACHIHIRO
OSUGA KAZUTOYO
Next Patent: IGNITION DEVICE FOR INTERNAL COMBUSTION ENGINE